This Synthetic 'Chameleon Skin' Will Change How You See Colors
The public is only just now learning how the unique skin of chameleons can change color. Now, researchers are also revealing that they are in the midst of imitating this strategy for our own use, creating ways to display color never before seen outside of nature.
In a study recently published in the journal Optica, researchers and engineers from the University of California at Berkeley have unveiled an incredibly thin material that can change color on demand when it's simply twisted or pulled.
"This is the first time anybody has made a flexible chameleon-like skin that can change color simply by flexing it," researcher Connie J. Chang-Hasnain, who co-authored the study, proudly announced in a statement.
So what about it makes it so similar to chameleon skin? Just yesterday, Nature World News reported how researchers determined that chameleons achieve their stunning and accurate array of colors to match their environment in a beautiful marriage between standard pigment shifts (like those seen in squid and cuttlefish) and the restructuring of tiny, light-reflecting crystals.
This second part, physicist Jérémie Teyssier and biologist Suzanne Saenko had explained, take care of colors that cannot be so easily made with natural pigment alone - blue and violet being two of these notorious hues.
The micro-crystals, laced throughout a chameleons skin, change what color light they reflect - the color we see - depending on how taut or lose the skin is. In this way, the crystals serve almost like a "selective mirror," augmenting what color is seen with the addition of what a lizard's natural pigments reflect. (Scroll to read on...)
The new material, however, only makes color with this second "mirror" approach, which is what makes it particularly special to industries trying to avoid costly chemicals.
Foregoing pigments and dyes entirely, the Berkeley team etched rows of ridges onto a single, thin layer of silicon. The ridges then reflect very specific wavelengths of light depending on how they are physically manipulated (i.e. twisting or flexing the silicon).
"If you have a surface with very precise structures, spaced so they can interact with a specific wavelength of light, you can change its properties and how it interacts with light by changing its dimensions," Chang-Hasnain explained.
What's interesting is that this has actually been an idea in the making for a while, long before the secret to chameleon color was revealed.
Certain insects and even birds, like blue jays, also boast "structural color" where things like chitin structure or feather design reflect light at very specific frequencies to achieve vibrant reflections of light.
Chang-Hasnain and her colleagues actually determined that you could change colors by manipulating these fixed structures even before it was revealed that this is exactly what the chameleon does - a rare moment when man and nature think alike without one actually inspiring the other.
The greatest challenge that remains is ensuring that the light reflected with each exact manipulation is pure and consistent. Past work looked into trying this approach with metals and other hardy, but flexible materials. But silicon reflects up to 83 percent of incoming light, making it capable of achieving more vibrancy than other viable options.
The researchers press that this new material-of-many-colors offers intriguing possibilities for an entirely new class of display technologies, color-shifting camouflage, and sensors that can detect otherwise imperceptible defects in buildings, bridges, and aircraft.
"This is the first time anyone has achieved such a broad range of color on a one-layer, thin and flexible surface," Change-Hasnain added. "I think it's extremely cool."
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